June 2017 LSAT
Section 4
Question 7
Which one of the following could be true?
Reply
Irina on September 17, 2019
@Ryan-Mahabir,This game requires us to determine the order of seven musicians - L M N O P S T. The following rules apply:
(1) L must perform earlier than N
L< N
We can infer that N cannot perform 1st, and L cannot perform 7th.
(2) M must perform earlier than T
M
We can infer that M cannot be 7th, and T cannot be 1st.
(3) There must be exactly one performance between O & L
L _ O or O_L
(4) There must be exactly one performance between M & P
M_P or P_M
(5) P must perform 1st or 7th.
P -1 v 7
So we can infer that M must perform 3 or 5 per rule (4).
Let's diagram all the rules together:
___ ___ ___ ___ ___ ___ __
1 2 3 4 5 6 7
/P /M /M /P
~N ~L
~T
Let's look at the answer choices:
(A) M performs 4th.
Impossible. M must be 3d or 4th per rules (3) and (5).
(B) N performs 1st.
Impossible. N cannot be #1 per rule (1).
(C) O performs 5th.
Since L cannot be 7th, the only way O could be 5th is if L is 3d but then there is no place left for M with both 3d and 5th spot taken, hence this scenario is also impossible.
(D) S performs 7th.
If S performs 7th, P must be 1st, M must be 3d, Then L & O could be #2 and #4, and N & T #5 and #6. Since this scenario complies with all the rules, (D) is the correct answer.
P L M O N T S
1 2 3 4 5 6 7
(E) T performs 2d.
Impossible. If T performs 2d, M must perform 1st per rule (2) but per rules (4) (5), only one performance can separate M & P and P must be 1st or 7th. If M is #1, it will force P into #3 slot, which violates rule (5). We can thus conclude that T cannot be #2.
M T P
1 2 3 4 5 6 7
Let me know if this makes sense and if you have any further questions.